In order for a light-emitting device to generate light of multiple colors or color temperatures and thereby provide rich or diverse lighting effects, one conventional approach is to dispose at least two LED chips on a substrate and cover the LED chips and the substrate with an encapsulant, wherein the LED chips themselves can emit light of different colors respectively or can work in conjunction with phosphor powder to generate light of different colors. If, however, the LED chips are not properly arranged on the substrate, the light emitted by one of the LED chips may fall on the other LED chip or the neighboring phosphor powder, producing unexpected light that compromises the colors or color temperatures of the light of the light-emitting device.
Moreover, a conventional light-emitting device with multiple LED chips generally includes an epoxy molding compound (EMC) lead frame, to which the LED chips are directly bonded. More specifically, all the LED chips are bonded to a recessed area of the lead frame, with bonding wires of the LED chips taking up certain space of the recessed area. The recessed area, therefore, must be large enough for both the LED chips and the bonding wires, and the resulting lead frame package must have thick sidewalls, giving rise to the bulkiness of the conventional light-emitting devices. Furthermore, when a light-emitting device includes multiple LED chips, the heat generated by the LED chips during operation may impair the light emission efficiency and service lives of the LED chips if not properly dissipated.
In the light of the above, it is important for the related industries to develop a light-emitting device and/or an LED package structure capable of overcoming the aforesaid drawbacks.